Vacuum relay



Dec. 15, 1964 J PERRY ETAL 3,161,749

VACUUM RELAY Filed April 30, 1962 //V|/E/V70R$.

JOHN T. PERRY CHESTER J. KAWIECKI BY BUCK HORN, CHE A THAM a BLORE A TTORNE YS United States Patent 3,161,749 VACUUM RELAY John T. Perry,Bellwood, and Chester J. Kawiecki, Chicago, Ill., assignors to ZioslynManufacturing and Supply (30., Chicago, lill., a corporation of IllinoisFiled Apr. 30, 1962, Ser. No. 190,927 8 Claims. (Cl. 280-144) Thepresent invention relates to electrical devices and more particularly tovacuum relays.

An object of the present invention is to provide a new and improvedvacuum relay.

Another object of the present invention is to provide a vacuum relaycapable of operating at relatively high currentand voltage loads.

Still another object of the present invention is to provide a relayhaving relatively low internal reactance.

A further object of the invention is to provide a relay that may bemanufactured at a relatively low cost.

Another object of the present invention is to provide a relay having aminimum of moving parts and which may be operated a maximum number oftimes without failure.

Still another object of the present invention is to provide a relayconstruction that permits of easy and ready manufacture and assembly ofthe parts thereof.

A further object of the invention is to provide an extremely ruggeddesign capable of withstanding severe vibration and shock conditions.

Still other objects and advantages of the present invention willbecomemore apparent hereinafter.

The illustrated embodiment of the present invention comprises afour-pole, double throw relay though it will be apparent that theprinciples of the relay can be adapted to a single-pole, single throwtype or other pole and throw arrangement. The illustrated relaycomprises a glass envelope which forms a support for the contactelements each of which extends through the envelope to provide forelectrical connection thereto. A plurality of movable contact elementsare provided each of which includes a plate-like strip of suitablematerial such as molybdenum supported at one end and which may be flexedaxially of the envelopeto make or break engagement with a fixed contactelement. The movable contact elements are engaged in their free ends inan insulating rod, axial movement of which causes switching movement ofthe movable contacts. The rod is mounted upon a bellows fixed to an endplate closing the envelope. The bellows is secured to a magnetic discwith which a coil is associated to pull bellows outwardly uponenergization of the coil so as to eifect movement of the rod and movablecontacts in the corresponding direction. Upon de-energization of thecoil the external air pressure upon the same causes bellows and rod andcontacts to move therewith in the opposite direction.

For a more detailed description of the invention reference is made tothe accompanying drawings and the following detailed description.

In the drawings:

FIG. 1 is a longitudinal section of a relay made in accordance with theinvention;

FIG; 2 is a sectional view taken along line 2-2 of FIG. 1; and

FIG. 3 is a sectional view taken along line 3--3 of FIG. 1.

To illustrate the invention there is shown in the drawing a relaycomprising an evacuated envelope including a dielectric bulb havingvatubular or cylindrical wall portion 12. The bulb may be made of anysuitable material and preferably it is made of a glass havingcharacteristics which will permit ready sealing of the glass 3,161,749Patented Dec. l5, 1964 to the various metallic elements that have to beconnected thereto. The wall portion 12 is connected at its lower endthrough a glass-to-metal seal to a ring 14, preferably of molybdenum,which is in turn brazed or welded to a flange 16 which may be formed ofMonel metal. The flange 16 is brazed or welded to a Monel ring 18supporting a cup-like housing 20 which may also be of Monel. The flange16, ring 18 and housing 20 define in effect an end wall for the.evacuated envelope.

The upper end portion 22 of the housing is of a re duced diameter and isprovided in the end wall 24 thereof with an opening 26 through which mayslide the supporting stem 28 of a switch actuator member or rod to bedescribed in greater detail hereinafter. The lower end of the stem 28 issecured to a cylindrical plate or element 30 of soft iron or othersuitable magnetic material. Extending between the end wall 24 and theplate 30 and hermetically sealed to both is a bellows 32 which willpermit axial movement of the stem 28 and plate 30. A flange 34 may beprovided on the stem 28 to limit the upward movement of the stem uponengagement with the wall 24.

Mounted within the lower portion of the housing 20 is an actuatingmechanism comprising a coil assembly H including an iron shell and acore 42 mounted on an end plate 44. The core 42 is surrounded by a coilindicated at 46. As will be apparent, the core 42, end plate 44, shell40 and plate '30 form a magnetic circuit. The shell 40 and otherportions of the actuating mechanism are removably secured within thehousing 20 by means of a snap ring 48 fitting within a groove in atubular extension 56 ofthe housing 20. External threads 52 may beprovided on the extension for mounting of the relay.

Fixed to and extending upwardly from the stem 28 is an actuator rod 60preferably formed of a non-conductive ceramic and which, as may be seenin FIG. 3, is oblong in cross section but symmetrical about its axis,the axis of the rod 64) being coincident with the axis of the bulb iii.The opposite narrow edges of the rod 60 are provided with two pairs ofopposite, co-planar, axially perpendicular, transverse slots 62, 64 and66, 68.

Hermetically sealed in the bulb 10 are a plurality of movable contacts71, 72, 73 and 74 which include rigid, rod-like supporting ;means orposts 75, 76, 77 and 78, respectively, which extend outwardly of thebulb 10 through the sidewall thereof. Fixed in the .end of the posts arethin, plate-like switching elements 82, 84; 86, 88 which areperpendicular to the actuator axis and the distal ends of which extendinto the slots 62, 64, 66 and68,.respectively. Such slots have a heightsomewhat greater than the thickness of the switching ele-' ments, asbest shown in FIG. 1, to permit sliding of such elements in and out ofthe slots as the rod moves axially. The switching elements preferablyare formed of molybdenum or similar material having sufficientflexibility for the purpose to become apparent and the posts are formedof tungsten. As will be apparent, vertical movement of the actuator rod60 will cause corresponding flexing of the elements 82-88.

As shown, the switching elements are arranged in two opposing pairs, theelement 84 being opposite the element 82 and theelement 86 opposite the"element 88, the elements 84, 86 being alignedaxially of the bulb as arethe elements 82, 88. Fora purpose to be explained the opposed elementsare spaced from one another by a distance slightlyg'reater than thethickness of the actuator cylindrical'tungsten rods, one of the contacts92 extending above and the other contact 94 extending below the switchelement 82 (see FIG. 2), the axes of the contacts being substantiallyparallel to planes normal to the actuator rod 60 and to the switchelement 82. The contacts 92, 84 are spaced apart a slight distancevertically, the spacing being greater than the thickness of the element82, and they each extend outwardly of the bulb so as to permitelectrical connections to be made thereto.

The contact 92 is so positioned with relation to the switch element 82;that the latter will engage the contact 92 when the flange 34 of theactuator rod stem 28 engages the housing end wall 24. When the contactsare so engaged, an electrical circuit between contact 92 and contact 71is closed. The contact 94 is positioned so that it will be engaged bythe switching element 82 as the latter is moved downwardly by movementof the magnetic element 30 on the lower end of the stem 28 intoengagement with the armature 42. This latter action will occur, ofcourse, when the magnet coil 46 is energized. Engagement of theswitching element 82 with the contact 94 will close a circuit throughthe contacts 71, 94. Upon de-energization of the coil 46 the externalair pressure acting upon the plate 30 and diaphragm 32 will move theactuator rod 60 upwardly to return the switch element 82 to the positionshown in FIG. 1 in engagement with the contact 92 thus opening thecircuit through contacts 71, 94 and reclosing a circuit through contacts71, 92. Thus, as is apparent, switching will occur by alternateenergization and de-energization of the coil 46.

Similarily arranged with the switch elements 84, 86 and 88 are otherpairs of electrodes or contacts indicated generally by the referencenumeral 100. While the illustrated relay is of a four pole, double throwtype it will be obvious that the arrangement of the invention is adaptedto other types of relays. As will be apparent from FIG. 3, the fixedcontacts extend angularly across the flexible contacts and outwardly ofthe envelope at points spaced circuferentially from the movable contactsso that a relatively long path exists between such electrodes thusminimizing the possibility of a breakdown occurring along the surface ofthe envelope between electrodes.

In assembling the relay of the invention the bulb 10 is first prepared,the various electrical contacts sealed therein and the mounting ring 14secured to the end of the bulb and the flange 16 brazed thereto. Sincethe portions of the electrical contacts extending through the bulb areof tungsten and the ring 14 is of molybdenum the bulb may be formed of asingle type tungsten sealing glass such as Corning type 3320. Next thehousing 20 is prepared with the flange 18 hermetically secured theretoand the bellows 32 mounted thereon with the actuator rod 60 mounted andsecured upon the bellows. The housing 20 and actuator rod are theninserted within the bulb 10 with the actuator rod positioned so that itis rotated 90 with respect to its operative position, the latterposition being shown in FIG. 3. Since the thick ness of the actuator rodis less than the distance between the ends of the opposing pairs, 82, 84and 86, 88, of the switching elements the rod can be slipped upwardlyinto its operative vertical position and then rotated 90 so as to engagethe movable contacts within the respective grooves 62-28. At that pointthe flanges 16, 18 will be in contact and the same can be heliarc weldedor otherwise suitably secured together so that the lower end of theenvelope will be vacuum tight. Thereafter, the envelope can be evacuatedthrough the tubulation in dicated at 98; and which is finally sealed offwhen the desired degree of evacuation is obtained. Finally the coilassembly can be inserted in the cavity provided and secured in place bythe ring 48. As will be apparent the coil assembly may be easily andquickly replaced.

It will be observed that the switching elements 82-88 make a lineengagement with the fixed contactsthereby 4.- minimizing contactresistance and the wattage loss within the device. A relay such as shownis capable of operating at loads of the order of 20,000 volts and 20amperes. Inasmuch as the actuator rod assembly is relatively light inweight it has a relatively low inertia enabling fast response toenergization or de-energization of the coil and contact chatter duringthe periods of vibration will be minimized.

Having illustrated and described a preferred embodiment of theinvention, it should be apparent that the invention permits ofmodification in arrangement and detail. We claim all such modificationsas come within the true spirit and scope of the appended claims.

We claim:

1. In avacuum relay,

an evacuated envelope including a dielectric bulb having a cylindricalwall portion,

means defining an end wall sealed to one end of said bulb,

said end wall having an opening therein coaxial with the axis of saidcylindrical wall portion,

a bellows hermetically sealed at one end thereof to the outer surface ofsaid end wall about said opening,

said bellows being positioned outwardly of said wall,

a circular magnetic plate sealed to and closing the opposite end of saidbellows,

a rigid fixed contact mounted in said bulb,

a movable contact mounted in said bulb for movement into and out ofengagement with said fixed contact,

an actuator rod operatively connecting said movable contact to saidmagnetic plate,

magnetic means mounted on said end wall for moving said magnetic plateincluding a core mounted adjacent said magnetic plate, and adapted uponenergization to move said plate outwardly, a'coil surrounding said corefor energizing said core, and a housing of magnetic material surroundingsaid core and coil.

2. In a vacuum relay,

a tubular dielectric bulb,

an actuator rod mounted coaxially in said bulb for movement in the axialdirection,

said actuator rod comprising a dielectric portion of oblongconfiguration in cross section and symmetrical about said axis, said rodportion having a pair of coplanar, axially perpendicular transverseslots in the opposite narrower ends thereof,

a pair of diametric movable contact elements each having an end portionreceived one in each of said slots, electrically conductive meansfixedly supporting the gpplpsing ends of said contact elements from saidthe opposing ends of said contact elements being spaced apart a distanceno less than the lesser width of said actuator rod portion whereby saidrod may be disengaged from said contacts by rotating the rod about itsaxis.

3. In a vacuum relay,

an envelope including a dielectric bulb having a cylindrical wallportion,

means defining an end wall sealed to one end of said bulb,

said end wall having an opening therein coaxial with the axis of saidcylindrical wall portion,

a bellows hermetically sealed at one end thereof to the outer. surfaceofsaid end wall about said opening, said bellows being positionedoutwardly of said wall, a circular magnetic plate sealed to and closingthe opposite end of said bellows,

a fixed contact mounted in said bulb,

a movable contact mounted in said bulb for movement axially of said bulbinto and out of engagement with said fixed contact, I

each of said contacts including a portion sealed in said bulb andextending outwardly thereof and forming an electrical connection forsaid contacts,

an actuator rod operatively connecting said movable contact to saidmagnetic plate,

and magnetic means operatively arranged with said magnetic plate forefiecting outward movement of said magnetic plate.

4. A vacuum relay comprising:

an envelope including a'dielectric bulb having a cylindrical wallportion,

an actuator housing sealed to one end of said Wall portion, and definingan end wall,

said housing end wall having .an opening therein coaxial with the axisof said cylindrical wall portion,

a bellows hermetically sealed at one'end thereof to the outer surface ofsaid end wall about said opening extending outwardly of said wall,

a magnetic plate sealed to the opposite end of said bellows,

a movable contact mounted on said bulb wall portion and having a portionextending exteriorly of the envelope to permit electrical connectionthereto,

said movable contact comprising a mounting portion mounted in fixedposition in said bulb and a flexible, plate-like element extending fromsaid mounting portion and capable of flexing in the axial direction ofsaid bulb,

a pair of rigid, fixed contacts mounted on said bulbwall portion withone of said fixed contacts on each of the opposite sides of said movablecontact element,

each of said fixed contacts extending outwardly of said bulb andconstituting an electrical lead,

an actuator rod mounted on said magnetic plate and extending throughsaid opening coaxially with said envelope wall portion,

said rod comprising a dielectric portion having a slot therein receivingthe distal end of said movable contact,

and a magnetic coil mounted in said actuator housing in operativerelation with said plate whereby upon energization of said coil, saidplate is attracted thereto to move said rod axially thereby moving saidmovable contact in one direction and upon de-energization of said coilsaid plate is moved by external air pressure in the opposite directionthereby moving said movable contact in said opposite direction.

5. In a vacuum relay,

an envelope including a tubular dielectric bulb including an open end,

a fixed contact in said bulb,

a movable contact in said bulb,

an actuator element in said bulb movable axially thereof and operativelyconnected to said movable contact to effect movement thereof into andout of engagement with said fixed contact,

a wall member of non-magnetic material,

a tubular ring securing said wall member to said bulb end,

said wall member being reentrant and defining an outer cup-shapedhousing coaxial with said bulb and opening outwardly with respectthereto and an inner, coaxial cup-shaped housing of smaller diameterthan said outer housing, the inner end of said inner housing having acoaxial opening therein to the said bulb,

a bellows mounted coaxially in said inner housing, one end of saidbellows being sealed to the edge of the said opening in the inner end ofsaid housing,

a disc of magnetic material sealed to the opposite end of said bellows,said disc being substantially in the plane of the inner end of saidouter housing,

said actuator element being secured to said disc whereby axial movementof said disc causes axial movement of said actuator element,

and magnet means for effecting outward movement of said disc,

said magnet means comprising a housing of magnetic material cylindricalin configuration fitting snugly within said outer housing, said magnetmeans housing having an inner end wall provided with a coaxial openingof a diameter just slightly greater than said disc whereby said disc maymove freely within said opening axially thereof,

a coaxial magnetic core in said magnet means spaced axially from saiddisc and a coil surrounding said core, whereby upon energization of saidcoil said disc will be drawn outwardly relative to said bulb and upondeenergization of said coil the exterior air pressure upon saiddiaphragm will cause said disc to move inwardly relative to said bulb.

6. Ln a vacuum relay,

an envelope including a tubular bulb formed solely of dielectricmaterial,

an actuator rod mounted in said bulb,

means operatively connected to said rod for effecting axialreciprocation thereof,

said rod comprising a dielectric portion having an axially perpendicularslot in the periphery thereof,

a flexible, plate-like switching element of electrically conductivematerial having an end portion extending into said slot, 7

said slot being of slightly greater height than the thickness of saidelement whereby the latter may slide within said slot,

support means fixedly supporting the opposite end of said switchingelement from said bulb,

said support means comprising a rigid, rod-like post extending into saidbulb through the sidewall thereof and sealed therein,

a rigid, fixed contact positioned adjacent said switching element forengagement and disengagement by said switching element as said actuatorrod is reciprocated,

said fixed contact comprising a cylindrical rod the longitudinal axis ofwhich is substantially parallel to the plane of said switching element,

said fixed contact rod extending outwardly of said bulb sidewall at apoint spaced circumferentially from said support meansv 7. An electricalswitch comprising an evacuated envelope including an elongated sidewalldefining tubular dielectric portion,

an actuator member in said envelope mounted for movement in a directionparallel to the axis thereof,

means operatively connected to said actuator member for moving the samebetween two axially spaced positions,

a movable contact member including a rigid, rod-like conductive mountingportion hermetically sealed in said sidewall defining dielectric portionand extending within and without said envelope,

said movable contact member including a flexible contact portion havingone end fixed to said movable contact mounting portion,

said flexible contact portion being engaged by said actuator member at apoint remote from said mounting portion so that axial movement of saidactuator member causes corresponding axial movement of said flexiblecontact portion,

and a fixed contact comprising a rigid, rod-like member hermeticallysealed in said sidewall defining dielectric portion at a point spacedcircumferentially from said movable contact support portion andextending within and without said envelope,

said fixed contact extending angularly across said flexible contactportion within the limits of movement of said flexible contact portionso as to be engaged by said flexible contact portion in one position ofsaid actuator member and so as to be spaced from 6 said flexible contactportion in the other position of said actuator member.

8. An electrical switch comprising an evacuated envelope including anelongated tubular sidewall defining dielectric portion,

an actuator member in said envelope mounted for movement in a directionparallel to the axis thereof,

means operatively connected to said actuator member for moving the samebetween two axially spaced positions,

a movable contact member including a rigid, rod-like conductive mountingportion hermetically sealed in said sidewall defining dielectric portionand extending within and without'said envelope,

said movable contact member including a flexible contact portion havingone end fixed to said movable contact mounting portion and the other endengaged by said actuator member so that axial movement of said actuatormember causes corresponding axial movement of said flexible contactportion,

and a fixed contact comprising a rigid, rod-like member hermeticallysealed in said sidewall defining dielectric portion at a point spacedcircumferentially from said movable contact support portion andextending within and without said envelope,

said fixed contact extending angularly across said flexis ble contactportion between said actuator member and said mounting portion andwithin the limits of movement of said flexible contact portion so as tobe engaged by said flexible contact portion in one position of saidactuator member and so as to be spaced from said flexible contactportion in the other position of said actuator member.

References Cited in the file of this patent UNITED STATES PATENTS2,886,668 Steward et al May 12, 1959 2,905,788 Harrison Sept. 22, 19592,908,780 Walters Oct. 13, 1959 2,938,092 Steward May 24, 1960

1. IN A VACUUM RELAY, AN EVACUATED ENVELOPE INCLUDING A DIELECTRIC BULBHAVING A CYLINDRICAL WALL PORTION, MEANS DEFINING AN END WALL SEALED TOONE END OF SAID BULB, SAID END WALL HAVING AN OPENING THEREIN COAXIALWITH THE AXIS OF SAID CYLINDRICAL WALL PORTION, A BELLOWS HERMETICALLYSEALED AT ONE END THEREOF TO THE OUTER SURFACE OF SAID END WALL ABOUTSAID OPENING, SAID BELLOWS BEING POSITIONED OUTWARDLY OF SAID WALL, ACIRCULAR MAGNETIC PLATE SEALED TO AND CLOSING THE OPPOSITE END OF SAIDBELLOWS, A RIGID FIXED CONTACT MOUNTED IN SAID BULB, A MOVABLE CONTACTMOUNTED IN SAID BULB FOR MOVEMENT INTO AND OUT OF ENGAGEMENT WITH SAIDFIXED CONTACT, AN ACTUATOR ROD OPERATIVELY CONNECTING SAID MOVABLECONTACT TO SAID MAGNETIC PLATE, MAGNETIC MEANS MOUNTED ON SAID END WALLFOR MOVING SAID MAGNETIC PLATE INCLUDING A CORE MOUNTED ADJACENT SAIDMAGNETIC PLATE, AND ADAPTED UPON ENERGIZATION TO MOVE SAID PLATEOUTWARDLY, A COIL SURROUNDING SAID CORE FOR ENERGIZING SAID CORE, AND AHOUSING OF MAGNETIC MATERIAL SURROUNDING SAID CORE AND COIL.